Development of nickel–phosphorus coatings containing micro particles of talc phyllosilicates

Synthetic Talc and Talc‐Like Structures: Preparation, Features and Applications

“…composites were reported in the pioneering work of ag roup at Toyota in 1993). [24][25][26][27] To satisfy these requirements, possible means have been put forward:i )the need for high purity talc was solved by the exploration of new highly pure talc deposit [28,29] and/or the improvements of techniques to purify talcore deposits; [30] ii)talc dispersion in an aqueous medium was improved by using surface-treatment such as pre-coating by carboxyl methyl cellulose adsorption,f or example; [31][32][33] and iii)the need for submicronic talc particles has led to the development of grinding processes such as air jet milling, [34,35] sonication, [36] stirred ball milling [37] and dry milling. [38] Alternatively, the company Nanova has developed am echanical-chemical process to reduce particles ize and increase the surfacea rea of talc.…”

In-situ SEM study of crack initiation, propagation and interfacial debonding of Ni-P coating during tensile tests: Heat treatment effect

“…This later has the effect of reducing the mismatch between steel and Ni-P, thus increasing the crack spacing [5].…”

“…Joel et al [5] estimated the ultimate shear strength of the electroless NiP coating deposited on steel to be equal to 1.1 and 1.21 GPa for an annealed sample at 420 and 600°C respectively. Yet, these numbers are questionable as they greatly exceed the shear strength level of steel.…”

“…Rolf Weil and Konrad Parker [2] considered that the structure of electroless Ni-P coating deposits was amorphous when the Phosphorus content exceeded 7%. The amorphous structure of the deposits was thermally unstable and could undergo a crystalline transition at moderate temperatures (300-400°C) [3,4,5,6]. In the case of thermal processing for improving deposit hardness, the typical temperature to achieve maximum hardness in electroless Ni-P deposits would be approximately 400°C for 1 h. Keong et al [7] attributed this growth of hardness to the crystallization of Nickel and the precipitation of fine particles of Ni 3 P. In addition, they reported that Ni 3 P, which was stable phase, had a higher strength and a shear modulus, causing a hardening effect on the coating.…”

“…Joel et al [5] conducted a series of experiments, using a microscopic tensile test, to explore the annealing temperature effect (420 and 600°C) into the cracking behavior of an electroless Ni-P layer on a low carbon steel substrate. They demonstrated that the annealing at 420°C caused an important improvement in the adhesion level of the coating and more precisely of the Ni-P matrix.…”